<template>
  <div class="pagination">
    <!-- <h1>
      start:{{ startNumAndEndNum.start }}---end:{{
        startNumAndEndNum.end
      }}---continues:{{ continues }}---startNumAndEndNum:{{ startNumAndEndNum }}
    </h1> -->
    <button
      :disabled="pageNo <= 1"
      :class="{ 'button-actives': activeUp }"
      @click="
        $emit('getPageNo', pageNo - 1);
        pageUp();
      "
    >
      上一页
    </button>
    <!-- <button>1</button> -->
    <button
      v-if="startNumAndEndNum.start > 1"
      @click="$emit('getPageNo', 1)"
      :class="{ active: pageNo == 1 }"
    >
      1
    </button>
    <i v-if="startNumAndEndNum.start > 2">···</i>
    <button
      v-for="(page, index) in startNumAndEndNumList"
      :key="index"
      @click="$emit('getPageNo', page)"
      :class="{ active: pageNo == page }"
    >
      <!-- v-if="page >= startNumAndEndNum.start" -->
      {{ page }}
    </button>
    <i v-if="startNumAndEndNum.end < totalPage - 1">···</i>
    <button
      v-if="startNumAndEndNum.end < totalPage"
      @click="$emit('getPageNo', 7)"
      :class="{ active: pageNo == 7 }"
    >
      {{ totalPage }}
    </button>
    <button
      :disabled="pageNo >= 7"
      @click="
        $emit('getPageNo', pageNo + 1);
        pageDown();
      "
      :class="{ 'button-actives': activeDown }"
    >
      下一页
    </button>

    <button style="margin-left: 3px">共 {{ total }} 条</button>
  </div>
</template>

<script>
export default {
  name: "Pagination",
  data() {
    return {
      activeUp: false,
      activeDown: false,
    };
  },
  props: ["pageNo", "pageSize", "total", "continues"],
  computed: {
    //totalPage——最大页数
    totalPage() {
      return Math.ceil(this.total / this.pageSize);
    },
    //起始与结束的计算
    startNumAndEndNum() {
      const { continues, pageNo, totalPage } = this;
      let start = 0,
        end = 0;
      //continues——连续的页码
      if (continues > totalPage) {
        start = 1;
        end = totalPage;
      } else {
        start = pageNo - parseInt(continues / 2);
        end = pageNo + parseInt(continues / 2);
        if (start < 1) {
          start = 1;
          end = continues;
        }
        if (end > totalPage) {
          end = totalPage;
          start = totalPage - continues + 1;
        }
      }
      return { start, end };
    },
    //计算遍历的次数
    startNumAndEndNumList() {
      const { startNumAndEndNum, pageNo } = this;
      const range = [];
      if (pageNo == 4) {
        for (
          let i = startNumAndEndNum.start;
          i <= startNumAndEndNum.end - 1;
          i++
        ) {
          range.push(i);
        }
      } else {
        for (let i = startNumAndEndNum.start; i <= startNumAndEndNum.end; i++) {
          range.push(i);
        }
      }
      return range;
    },
  },
  methods: {
    pageUp() {
      console.log(this.actives);
      this.activeUp = true;
      console.log(this.actives);
      setTimeout(() => {
        this.activeUp = false;
      }, 100); // 1秒后移除活动样式类
    },
    pageDown() {
      console.log(this.actives);
      this.activeDown = true;
      console.log(this.actives);
      setTimeout(() => {
        this.activeDown = false;
      }, 100); // 1秒后移除活动样式类
    },
  },
};
</script>
      
<style lang="less" scoped>
.pagination {
  text-align: center;
  button {
    margin: 0 5px;
    background-color: #f4f4f5;
    color: #606266;
    outline: none;
    border-radius: 2px;
    padding: 0 4px;
    vertical-align: top;
    display: inline-block;
    font-size: 13px;
    min-width: 45.5px;
    height: 28px;
    line-height: 28px;
    cursor: pointer;
    box-sizing: border-box;
    text-align: center;
    border: 0;

    &[disabled] {
      color: #c0c4cc;
      cursor: not-allowed;
    }

    &.active {
      cursor: not-allowed;
      background-color: #409eff;
      color: #fff;
    }
  }
  i {
    line-height: 28px;
    padding: 0px 4px;
  }
  .button-actives {
    background-color: #409eff;
    color: #fff;
  }
}
</style>
